My qh is a leader. I'd even say LEADER.
She was driving the pasture at the boarding farm after she just turned 2 years old and everyone else was following her. That was pretty hilarous to watch. Whenever I ride her with other horses I try to keep the distance because she states right away she IS a leader (and she's pretty small too).
My paint on other hand is a follower of the qh. BUT, I've seen her being extremely mean to other horses - attacked them and beat them up. She also broke my neighbor's fence by kicking at her bossy mare.
That was a shame, actually....